Study: Ants Cooled Earth’s Climate As Their Numbers Grew

TEMPE, Ariz. (CBS Las Vegas) – Ants may be cooling Earth’s climate as their numbers grow, a new study finds.

“Ants are changing the environment,” Ronald Dorn, a geologist at Arizona State University, and lead author on the study, told LiveScience.

Dorn discovered that when ants make limestones, a “weather” mineral in order to secrete calcium carbonate, they create a process that traps and removes a tiny bit of carbon dioxide gas from the atmosphere.

This is similar to carbon sequestration, which is a cooling process that takes place in the ocean.

Dorn was able to discover that ants are powerful weathering agents by tracking the breakdown of basalt sand. Twenty-five years ago Dorn buried sand at six locations throughout the Catalina Mountains in Arizona and Palo Duro Canyon in Texas. Dorn dug up some sand every five years to measure how much the minerals olivine and plagioclase have degraded from exposure to water, insect activity, and chemicals from tree roots, LiveScience reports.

Dorn revealed that ants appear to break down those minerals 50 to 300 times faster than sand left undisturbed. The ants were also breaking up the limestone with their nests.

Dorn thinks this process is a scientific mystery. He suggests that the ants are trapping carbon dioxide in the rock and that this transformation is taking place when the ants lick sand grains and stick them on the walls of their nests.

“We don’t know if they are licking it or pooping it, or if it’s bacteria in the ant’s gut or the fungi growing in the colonies,” Dorn told LiveScience.

Dorn knows more studies are needed on the role of ants and he is only speculating at this point on how ants that work in concert could have removed significant quantities of carbon dioxide from the atmosphere since the insects expanded their number starting 65 million years ago.

Dorn set out to show the effect that weathering minerals have on removing carbons from Earth’s atmosphere.

“Ants were not the original focus,” Dorn told LiveScience. “I’m a weathering nerd. What better way to figure out weathering than to observe it in situ?”